Association of soil selenium, strontium, and magnesium concentrations with Parkinson's disease mortality rates in the USA.

Among the 41 soil elements analyzed from 4856 sites across the contiguous 48 states, average Parkinson's disease (PD) mortality rates between 1999 and 2014 have the most significant positive correlation with the average soil strontium (Sr) concentrations (correlation r = 0.47, significance level p = 0.00), and average PD mortality rates have the most significant inverse correlation with the average soil selenium (Se) concentrations (r = -0.44, p = 0.00). Multivariate regression models indicate that soil Sr and Se concentrations can explain 35.4% of spatial disparities of the state average PD mortality rates between 1999 and 2014 (R 2 = 0.354). When the five outlier states were removed from the model, concentrations of soil Sr and Se can explain 62.4% (R 2 = 0.624) of the spatial disparities of PD mortality rates of the 43 remaining states. The results also indicate that high soil magnesium (Mg) concentrations suppressed the growth rate of the PD mortality rates between 1999 and 2014 in the 48 states (r = -0.42, p = 0.000). While both Se and Sr have been reported to affect the nervous system, this study is the first study that reported the statistically significant association between the PD mortality rates and soil concentrations of Se, Sr, and Mg in the 48 states. Given that soil elemental concentration in a region is broad indicator of the trace element intake from food, water, and air by people, implications of the results are that high soil Se and Mg concentrations helped reduce the PD mortality rates and benefited the PD patients in the 48 states.

Genotoxicity evaluation of two metallic-insecticides using Allium cepa and Tradescantia pallida: A new alternative against leaf-cutting ants.

In order to combat leaf-cutting ants, the pesticide sulfluramid used to be the most widely utilized active ingredient. However, its use was banned in 2009 by the Stockholm Convention, although some countries were allowed to continue using it. As an effective alternative to its replacement, researchers developed a metallic-insecticide system, which is a natural product linked to metal complexes. Thus, the aim of this study was to evaluate the ability of these new metallic-insecticides in change the genetic material of non-target organisms. The tests were performed utilizing chromosomal aberrations and micronucleus tests in the Allium cepa test system and the Trad-MCN test in Tradescantia pallida. To better understand the results, one of the components of the formula, 5-methyl-phenanthroline, was also analyzed according to the same parameters. To A. cepa, the results showed that one of the metallic insecticides induced cytotoxicity and genotoxicity at different concentrations, while the other metallic-insecticide showed chromosomal instability only at the highest concentration. The analysis of 5-methyl-phenanthroline revealed that it can be related with the positive results, since genotoxic effects were induced. In the Trad-MCN test, none of the metallic-insecticides showed genotoxic activity, although one of them induced more micronucleus formation.

Optimized in vitro procedure for assessing the cytocompatibility of magnesium-based biomaterials.

Magnesium (Mg) is a promising biomaterial for degradable implant applications that has been extensively studied in vitro and in vivo in recent years. In this study, we developed a procedure that allows an optimized and uniform in vitro assessment of the cytocompatibility of Mg-based materials while respecting the standard protocol DIN EN ISO 10993-5:2009. The mouse fibroblast line L-929 was chosen as the preferred assay cell line and MEM supplemented with 10% FCS, penicillin/streptomycin and 4mM l-glutamine as the favored assay medium. The procedure consists of (1) an indirect assessment of effects of soluble Mg corrosion products in material extracts and (2) a direct assessment of the surface compatibility in terms of cell attachment and cytotoxicity originating from active corrosion processes. The indirect assessment allows the quantification of cell-proliferation (BrdU-assay), viability (XTT-assay) as well as cytotoxicity (LDH-assay) of the mouse fibroblasts incubated with material extracts. Direct assessment visualizes cells attached to the test materials by means of live-dead staining. The colorimetric assays and the visual evaluation complement each other and the combination of both provides an optimized and simple procedure for assessing the cytocompatibility of Mg-based biomaterials in vitro.

Search and rescue response to a large-scale rockfall disaster.

OBJECTIVE: To describe the prehospital management and safety of search and rescue (SAR) teams involved in a large-scale rockfall disaster and monitor the acute and chronic health effects on personnel with severe dolomitic dust exposure. METHODS: SAR personnel underwent on-site medical screening and lung function testing 3 months and 3 years after the event. RESULTS: The emergency dispatch center was responsible for central coordination of resources. One hundred fifty SAR members from multidisciplinary air- and ground-based teams as well as geotechnical experts were dispatched to a provisionary operation center. Acute exposure to dolomite dust with detectable silicon and magnesium concentrations was not associated with (sub)acute or chronic sequelae or a clinically significant impairment in lung function in exposed personnel. CONCLUSIONS: The risk for personnel involved in mountain SAR operations is rarely reported and not easily investigated or quantified. This case exemplifies the importance of a multiskilled team and additional considerations for prehospital management during natural hazard events. Safety plans should include compulsory protective measures and medical monitoring of personnel.

Effects of magnesium, chromium, iron and zinc from food supplements on selected aquatic organisms.

The aim of this study was to determine the effect of uncontrolled environmental disposal of food supplements containing magnesium (Mg), chromium (Cr), iron (Fe) and zinc (Zn) on selected aquatic organisms including freshwater algae Scenedesmus subspicatus and Raphidocelis subcapitata, water flea Daphnia magna and duckweed Lemna minor. Thirty different food supplements containing Mg, Cr, Fe and Zn were analyzed. Results were expressed as effective concentration 50 (EC50), i.e. growth inhibiting Mg, Cr, Fe and Zn (mg/L) concentration immobilizing 50% of treated organisms. Particular metal EC50 differed significantly (p < 0.001) among study organisms, as follows (in ascending order): Scenedesmus subspicatus EC50 Fe (median 46.9 mg/L) < Zn (59.8 mg/L) < Mg (73.0 mg/L) < Cr (88.1 mg/L) (KW-H(3;120) = 36.856; p < 0.001); Raphidocelis subcapitata EC50 Fe (median 44.9 mg/L) < Zn (52.6 mg/L) < Mg (62.2 mg/L) < Cr (76.8 mg/L) (KW-H(3;120) = 44.0936; p < 0.001); Daphnia magna EC50 Zn (median 59.4 mg/L) < Cr (79.2 mg/L) < Fe (80.8 mg/L) Mg (82.0 mg/L) (KW-H(3;120) = 39.2637; p < 0.001); and Lemna minor EC50 Zn (median 131.0 mg/L) < Fe (186.8 mg/L) < Mg (192.5 mg/L) < Cr (240.4 mg/L) (KW-H(3;120) = 58.6567; p < 0.001). Uncontrolled environmental disposal of food supplements containing Mg, Cr, Fe and Zn exerts adverse effects on aquatic organisms. Therefore, legal provisions should regulate both the utilization and disposal of food supplements into the environment.

Estudio toxicológico del Calcidol, un suplemento nutricional de calcio y magnesio / Toxicological study of caldidol: a calcium and magnesium nutritional supplement

El calcio y el magnesio constituyen dos cationes esenciales para el organismo humano, los cuales se adquieren fundamentalmente a través de la dieta, pero en ocasiones se hace necesario su suplementación. El objetivo de este estudio es la evaluación de los posibles efectos tóxicos preclínicos de un suplemento oral de calcio y magnesio, el Calcidol. Se determinó la toxicidad aguda a través del ensayo límite a la dosis de 2000 mg/kg en ratas Wistar (Cenp:WIST) de ambos sexos, la irritación de la mucosa oral en hámsters Sirios Dorados machos (provenientes de CENPALAB, Cuba) mediante un ensayo agudo y a dosis repetidas y la toxicidad subcrónica oral en ratas Wistar de ambos sexos durante un período de 90 días con la administración de tres dosis (1280, 2560 y 5000 mg/kg/día). De modo general la administración aguda de las tabletas de Calcidol no provocó mortalidad ni manifestaciones tóxicas, resultando no irritante en la mucosa oral de hámster con un índice de irritación de 0,66 para el ensayo agudo y de 0,34 para el ensayo a dosis repetidas. En el ensayo de toxicidad subcrónica la mayor dosis administrada (5000 mg/kg/día) no produjo efectos tóxicos significativos reflejándose un comportamiento normal de ganancia de peso, consumo de alimentos y ausencia de signos tóxicos y mortalidad atribuible a la sustancia de prueba. Por otra parte se observó un aumento del pH urinario y una hipercelularidad fisiológica del tiroides, además de alteraciones histopatológicas a nivel de riñón las cuales constituyen una alerta para mantener una especial vigilancia sobre estos órganos diana en estudios posteriores (AU)

Evaluación toxicológica de las tabletas de Acimín: un suplemento nutricional de calcio magnesio de origen natural / Toxicological evaluation of Acimin tablets: a calcium and magnesium suplement of natural origin

Las sales de calcio y magnesio son utilizadas como suplementos nutricionales obtenidas a partir de fuentes naturales dentro de las cuales se encuentra la dolomita, la cual es un mineral formado por un complejo doble de carbonato de calcio y magnesio. En la formulación de suplementos nutricionales a partir de la dolomita y en la búsqueda de una mayor biodisponibilidad, se obtuvo una materia prima en forma de citrato de calcio y magnesio a partir de la dolomita, la cual fue utilizada para la fabricación de las tabletas masticables de Acimín. El objetivo de nuestro estudio se centró en la evaluación toxicológica preclínica de estas tabletas, para lo cual se realizó un ensayo de toxicidad aguda oral en ratas Wistar de ambos sexos administrando la dosis de 2000 mg/kg, un ensayo de irritación de mucosa oral a dosis repetidas en hámsters Sirios Dorados hembras y un ensayo de irritacion de mucosa gástrica en ratas istar machos (250 - 300 g), aplicando las dosis de 2000, 1000 y 500 mg/kg. Como resultado se obtuvo que las tabletas de Acimín no poseen toxicidad significativa en el ensayo de toxicidad aguda oral (DL50>2000 mg/kg), no son irritantes de la mucosa oral (índice de irritacion de 0) y producen acidez e irritación sobre la mucosa gástrica a la dosis de 2000 mg/kg (AU)

NMDA receptor complex blockade by oral administration of magnesium: comparison with MK-801.

The ion channel of the N-methyl-D-aspartate (NMDA) receptor complex is subject to a voltage-dependent regulation by Mg2+ cations. Under physiological conditions, this channel is supposed to be blocked by a high concentration of magnesium in extracellular fluids. A single dose of magnesium organic salts (i.e., aspartate, pyroglutamate, and lactate) given orally to normal mice rapidly increases the plasma Mg2+ level and reveals a significant dose-dependent antagonist effect of magnesium on the latency of NMDA-induced convulsions; this effect is similar to that seen after administration of the dizocilpine (MK-801) channel blocker. An anticonvulsant effect of Mg2+ treatment is also observed with strychnine-induced convulsions but not with bicuculline-, picrotoxin-, or pentylenetetrazol-induced convulsions. In the forced swimming test, Mg2+ salts reduce the immobility time in a way similar to imipramine and thus resemble the antidepressant-like activity of MK-801. This activity is masked at high doses of magnesium by a myorelaxant effect that is comparable to MK-801-induced ataxia. Potentiation of yohimbine fatal toxicity is another test commonly used to evaluate putative antidepressant drugs. Administration of Mg2+ salts, like administration of imipramine strongly potentiates yohimbine lethality in contrast to MK-801, which is only poorly active in this test. Neither Mg2+ nor MK-801 treatment can prevent reserpine-induced hypothermia. These data demonstrate that oral administration of magnesium to normal animals can antagonize NMDA-mediated responses and lead to antidepressant-like effects that are comparable to those of MK-801. This important regulatory role of Mg2+ in the central nervous system needs further investigation to evaluate the potential therapeutic advantages of magnesium supplementation in psychiatric disorders.

Potentiation of magnesium-deficiency-induced foetotoxicity by concomitant iron deficiency and its prevention by adequate supply via drinking water.

Magnesium (Mg) and iron (Fe) deficiency frequently develop during pregnancy. Therefore these factors were studied alone (Mg-L, resp. Fe-L) or in combination (Mg-L/Fe-L) on 16 female and 8 male adult fertile Sprague-Dawley rats. The animals were offered a basal diet containing 30 per cent and 17 per cent of the rat's requirement for magnesium and iron, respectively, starting 21 days before mating (2:1) until 49 days after mating. Offspring were also kept on this regimen during a 3-week lactation period and 7 days post weaning. Drinking water was either enriched with 101 ppm Fe2+ (ferrous gluconate): Mg-L, or 365 ppm magnesium (magnesium-L-aspartate hydrochloride trihydrate, MAH): Fe-L, or with any: Mg-L/Fe-L or with both electrolytes: Controls. Fertility remained unaffected under these conditions. Clinically, Fe-L induced iron deficiency and growth retardation of offspring. Pronounced reproductive toxicity was elicited by Mg-L and was even potentiated by Mg-L/Fe-L. In the parental generation, too, adverse effects of Mg-L were aggravated by Mg-L/Fe-L despite the fact that no iron accumulation occurred. Bioavailability of iron was not impaired by magnesium as MAH. With respect to human pregnancy magnesium supplementation has higher priority over iron supplements. To improve tolerance and compliance both minerals are suggested to be taken simultaneously.

Rat lung reactivity to natural and man-made fibrous silicates following short-term exposure.

The inflammatory and fibrogenic potential of three naturally occurring and two man-made industrial minerals were compared. Groups of five rats each received respectively a single intratracheal instillation of saline (control), UICC chrysotile B asbestos, short chrysotile 4T30, attapulgite, xonotlite (a calcium silicate), and Fiberfrax (an aluminum silicate) at doses of 1, 5, and 10 mg. One month after the treatment, assessment of lung morphology and bronchoalveolar lavage were performed on each animal. Under these conditions, UICC chrysotile B at all doses tested (1, 5, and 10 mg) induced fibrotic lesions in bronchiolar tissues while short chrysotile 4T30 (1, 5, and 10 mg) caused focal accumulation of inflammatory cells in the alveolar structures but no apparent fibrosis. Compared to these positive reactions with different fibrogenicity, xonotlite caused minimal inflammatory reactions detectable only at high dose (10 mg) and by bronchoalveolar analysis. By contrast, the rat lung reacted more significantly to attapulgite and Fiberfrax although the tissue reaction differed considerably for these two materials. While attapulgite, at doses up to 10 mg caused minimal reactions characterized by mononuclear cell infiltration mainly in the alveolar structures, Fiberfrax at 1 mg and higher caused significant granulomatous reactions and the appearance of early fibrosis. Overall the order of lung biological reactivity observed for the various silicates was xonotlite much less than attapulgite less than short chrysotile 4T30 less than Fiberfrax less than UICC chrysotile B. These observations indicate that Fiberfrax, attapulgite, and, to a lesser extent, xonotlite are biologically active within the time span studied and potentially deleterious for lung tissue.

Effect of calcitonin on the magnesium-induced bone resorption in the mouse.

This study was performed to evaluate whether Mg directly influences the activity of bone resorbing cells in vivo. Young male mice were given oral Mg supplementation (10 mM) in drinking water for 14 days. In order to inhibit bone resorption, a group of animals received 1 IU/kg/day of salmon calcitonin (CT) concurrently with Mg supplementation. The effects of CT alone were also tested separately. Skeletal changes were evaluated by histomorphometric analysis of parameters of endosteal bone resorption and formation after double tetracycline and double 3H-proline labelings. Two weeks of Mg supplementation induced a significant increase in the number of acid phosphatase-stained chondroclasts (+21.1%) and osteoclasts (+12.2%) and in the extent of osteoclastic resorbing surface (+40.5%) without change in serum mineral concentrations. Treatment with CT alone decreased the number of actively resorbing chondroclasts by 11% and decreased the osteoclastic resorbing surface by 22.4% without change in the number of active osteoclasts. Despite this 'escape' phenomenon, treatment with CT concurrent with Mg administration completely abolished the stimulatory effect of Mg on bone-resorbing cells. CT also inhibited the Mg-induced stimulation of the bone mineralization rate and produced a slight inhibition of the bone matrix apposition rate. The data indicate that Mg activates the bone resorbing cells in vivo and that CT administration blunts the Mg-induced stimulation of bone resorption.

Potential toxicity due to dolomite and bonemeal.

Large amounts of dolomite and bonemeal are being consumed, especially by nutrition-conscious persons. The mineral content of commercial samples has been analyzed by different laboratories, and significant amounts of lead, arsenic, mercury, and other potentially toxic metals, which also exist in conventional vitamin-mineral and calcium supplements, were detected. Physicians must consider the possibility of unrecognized self-poisoning from the consumption of such substances, especially in the context of unexplained neurologic, gastrointestinal, cutaneous, and hematologic disorders. The use of dolomite and bonemeal by pregnant women, children with suspected milk allergy, and elderly persons requires careful evaluation.

Effects of feeding high magnesium to young dairy calves.

Holstein bull calves were fed 1, 2, and 4% supplemental magnesium as magnesium oxide. The control diet contained .3% magnesium and consisted of ground corn, soybean meal, cottonseed hulls plus mineral, vitamin, and antibiotic supplements. Diarrhea was the most obvious effect of high intake of magnesium. The extent and intensity of the diarrhea was related closely to the dietary magnesium content. High (2 and 4%) magnesium reduced feed consumption and weight gains. Although there were traces of blood in feces, no abnormalities were observed at autopsy. Large tubular sections of mucus were voided in the feces with a greater prevalance among calves fed 2 and 4% supplemental magnesium. Magnesium in plasma rose sharply in response to the increased intake of magnesium. In calves receiving the 4% added magnesium, the plasma values were triple those of controls. When high magnesium was fed, magnesium increased much more in urine than in plasma. Within 1 wk after calves were returned to control diet, magnesium in urine and plasma declined to control.